Electricity explained Batteries, circuits, and transformers

Batteries produce electricity

Batteries generate electricity using two different metals submerged in a chemical solution called an electrolyte. One end of the battery is attached to one of the metals, and the other end is attached to the other metal. A chemical reaction occurs between the metals and the electrolyte. This reaction causes one metal to release more electrons than the other.

Source: Adapted from National Energy Education Development Project (public domain)

The metal that releases more electrons develops a positive (+) charge, and the other metal develops a negative (-) charge. When a wire or an electrical conductor, connects one end of the battery to the other, electrons flow through the wire to balance the electrical charge.

An electrical load is any device that uses electricity to do perform work, such as a light bulb. If a light bulb is placed along the wire, the flowing electricity will power it on. Electrons flow from the negative end of the battery, through the wire and the light bulb, and back through the positive end, creating a continuous flow.

Electricity travels in circuits

For electricity to flow, it needs a complete path, or electrical circuit. The on-off switch on electrical devices either closes (turns on) or opens (turns off) this circuit:

• Turning off a light or device opens the circuit and stops electrons from flowing.
• Turning on a light closes the circuit, allowing electricity to flow from one wire, through the light bulb, and then through the other wire to complete the circuit.

Transformers help move electricity efficiently

To overcome the challenge of sending electricity over long distances, William Stanley invented the transformer. A transformer adjusts the voltage (electrical pressure) of electricity in power lines.

High-voltage transmission lines (the ones you see hanging between tall metal towers) carry electricity over long distances. Higher voltage electricity is more efficient and less expensive for long distance travel. Lower voltage electricity is safer to use in homes and businesses. Transformers play a crucial role by either increasing (stepping up) or reducing (stepping down) voltages as electricity travels from power plants to homes and businesses.